Multi-flame gas burners



June 5, 1956 J. H. FLYNN MULTI-FLAME CAS BURNERS 2 Sheets-Sheet 1 FiledJan. 29, 1952 June 5, 1956 J. H. FLYNN MULTI-FLAME GAS BURNERS 2Sheets-Sheet 2 Filed Jan. 29, 1952 United States Patent MULTI-FLAME GASBURNERS John H. Flynn, New Rochelle, N. Y.

Application January 29, 1952, Serial No. 268,759

13 Claims. (Cl. 158 115) This invention relates to multi-fiame burnersof the dual-pressure gas type, and more particularly to selfignitingburners of this type.

It is to this day the general practice to provide a separate pilotburner or burners alongside a multi-fiame utility burner or burners ofthis type for the ignition of the latter. This practice entails in allinstallations the costly provision and maintenance of a separate pilotburner or burners, and the latter also occupy in many industrialinstallations utility space which couldbe used to great advantage inbringing the multi-dame burner or burners into more effectiveheat-exchange'relation with work to be heated, or in simplifyingconveyor equipment which carries the work to be heated past themultiflame burner or burners.

Accordingly, it is an object of the present invention to embody a pilotburner or burners directly in a multiflame burner of this type, therebyto eliminate the extra cost involved in the provision and maintenance ofa separate pilot burner or burners, and also to obviate all practicalinconveniences or diiiicuities heretofore encountered in the provisionof a separate pilot burner or burners in many industrial installations.

It is another object of the present invention to have provisions in thegas-distributing casing or manifold of a dual-pressure gas burner ofthis type for the selective installation of a pilot burner tip or of autility burner tip among the installed utility burner tips for theselective use of the multi-fiame burner with or without. a pilot burner.

A further object of the present invention is to have provisions in thegas-distributing casing' of a. burner of this type for the selectiveinstallation of a plurality of pilot burner tips or of utility burnertips at spaced places among the installed utility burner tips for theselective use of the multi-name burner with one or more pilot burners.

Another object of the present invention is to provide for the selectiveuse in a burner of this type a pilot burner tip which consists of autility burner tip identical with the other utility burner tips, and anexceedingly simple adapter which may readily and instantly be assembledwith the utility burner tip into a pilot burner tip, or disassembledfrom the burner tip for further use of the latter as a utility burnertip.

It is another object of the present invention to have identicalprovisions in the gas-distributing casing of a burner of this type forthe correct reception of utility burner tips only, even at the place orplaces Where a pilot burner tip or tips may be installed, and to havefurther provisions in the casing at the place or places designated for apilot burner or burners for the selective reception thereat of theaforementioned adapter or adapters for pilot burner use, or of aplug-like fitting or fittings to permit the use of a utility burner tipor tips as such at the place or places designated for the selective useof a pilot burner tip or tips.

It is a further object of the present invention to have ice provisionsin a multi-fiame burner of this type for the assured and rapidpropagation of a momentary ignition flame or of a steady pilot iiame toall burner tips of the burner the instant they are supplied with gas.

Another object of the present invention is to provide on the outside ofthe gas-distributing casing of a burner of this type and between theburner tips thereof restricted channels to compel and accumulate thereinhighly flammable gas from the adjacent burner tips as' soon as thelatter are supplied with gas, thereby to assure rapid propagation of aame from one burner tip to all the remaining burner tips.

A further object of the present invention is to extend thesefiame-propagation channels to the pilot burner tip or tips of theaforementioned combined utility and pilot burner of this type.

lIt is still another object of the present invention to cover theaforementioned fiamepropagation channels throughout their lengths notonly to protect thein from dirt and other foreign matter, such asbrushedol`f excess solder in the manufacture of can bodies, forinstance, but also to provide for further and quicker accumulation ofgas in these channels and accordingly accelerated and unfailingpropagation of a iiame from one burner tip to all the remaining burnertips.

Further objects and advantages will appear to those skilled in the artfrom the following, considered in conjunction with the accompanyingdrawings.

In the accompanying drawings, in which certain modes of carrying out thepresent invention are shown for illustrative purposes:

Fig. 1 is a front viewy of a burner embodying the present invention;

Fig. 2 is an enlarged end view of the same burner as viewed in thedirection of the arrow 2 in Fig. 1;

Figs. 3, 4 and 5 arey enlarged cross-sections through the burner astaken on the lines 3 3, 4 4 and 5 5, respectively, of Fig. 1;

Fig. 6 is an enlargedl fragmentary section taken on the line 6 6 of Fig.4;

Fig. 7 is a fragmentary front View of a modified burner;

Fig. 8 is an enlarged end-view, partly in section, of the modifiedburner of Fig. 7, the section being taken on the line 8 8 of Fig. 7;

Fig. 9 is a fragmentary front view of another modified burner;

Fig. 10 is an enlarged end view, partly inV section, of the modifiedburner of Fig. 9, the section being taken on the line 10 10 of Fig. 9;and

Fig. 1l is an enlarged end View, partly in section, of still anothermodified burner.

Referring to the drawings, and more particularly to Figs. 1 to 5thereof, the reference numeral 2@ designates a dual-pressure gas burnerwhich comprises a burner casing or manifold 22 and a plurality of burnertips 24. The casing 22, which may conveniently be cast, has bottom,front, top, rear and end walls 26, 28, 3d), 32 and 34, respectively, andan internal partition Wall 36 which divides the casing into ahigh-pressure gas chamber 38 and a low-pressure gas chamber 4th. Thecasing 22, which may be provided with suitable mounting pads 42, hasalso a boss 44 which is internally threaded at 46 for the reception of aconduit 48 that is in communication with a gas main or any othersuitable supply of flammable gas under pressure. As shown in Fig. 4, theconduit 48 is in direct communication with the high-pressure chamber 38,and gas from the latter is admitted into the lowpressure chamber 40through a valve opening St) in the internal partition wall 36.Cooperating with a seat portion 52 of the valve opening 50 is thebeveled end 54 of a valve screw 58 which is threadedly received in therear wall 32 of the burner casing and locked in axially adjustedposition by nuts 60. While the beveled end 54 of the valve screw 58 isin normal use of the instant burner spaced from the seat 52 so as toadmit gas from the highpressure chamber 38 into the low-pressure chamber40, the valve screw 58 may, if desired for any purpose, be brought intoengagement with the seat 52 of the valve opening 50 so as to prevent gasfrom the high-pressure chamber 38 from entering the low-pressure chamber40.

The top wall 30 of the burner casing 22 is, in the present instance,smoothly rounded at the front, and is there provided with a plurality ofidentical parallel bores 62 which are preferably inclined as shown inFigs. 3 to 5. The bores 62, which in this instance are arranged in line,are adapted for the fitted reception of the heads 64 of thedual-pressure gas burner tips 24, respectively. Provided in thepartition wall 36 of the burner casing 22 in axial alignment with thebores 62, except the bores 62a and 62b thereof (Fig. l), are bores,68(Fig. 4) which are preferably tapped for the removable reception of thethreaded Shanks 70 of burner tips 24, respectively. Bores 62 and 68 thusprovide an axially aligned set of holes for reception of a burner tip inthe casing. Each of the burner tips 24 has an intermediate body portion72 seated in an annular recess 74 in the partition wall 36, and is alsoprovided with a longitudinal through-passage 76 leading to the iame end77 of the burner tip. Each burner tip 24 of the instant dual-pressuregas type is further provided in its head 64 with toothlike forma tions80 to define in the respective bore 62 aplurality of secondary orlow-pressure gas passages.

For operating the instant burner, the valve-screw 58 is so adjusted thatthe gas admitted into the low-pressure chamber 40 has sufficientpressure to sustain the secondary ames f' at the flame end 77 of eachburner tip 24 to an extent like or similar to that indicated indot-anddash lines in Fig. 4, while the pressure of the gas in thehigh-pressure chamber 38 is regulated, by a suitable valve in theconduit 48, for instance, so that a sharp and steady jet ame f of thedesired length is emitted from the flame end 77 of each burner tip 24.Thesecondary flames f from each burner tip 24 serve the well-knownpurpose of sustaining the associated jet flame f.

The burner is, in the present instance, also provided with a built-inpilot burner unit 90 (Fig. 3) so as to render the burner selfigniting.In this instance also, the burner casing 20 has provisions at more thanone place thereof for the selective reception of either a pilot burnerunit 90 or a dual-pressure gas burner tip 24, thereby affording theopporunity to provide the burner with more than one pilot burner unit atdifferent places thereof, or to provide the same with a single pilotburner unit at either one of these places. Further in accordance withthe present invention, each pilot burner unit 90 comprises adual-pressure gas burner tip 24 and a structurally simple adapter 92.

For the selective reception of a pilot burner unit or units 90, thebottom wall 26 and partition wall 36 of the casing 22 are provided withsets of bores 94 and 96, respectively, of which the bores of said setsare axially aligned with the bores 62a and 62b, respectively (Figs. 1, 3and 5). The bores 94 in the bottom Wall 26 of the burner casing extend,in the present instance, through inclined bosses 98 and 100,respectively, on the casing, and are tapped for the removable mountingof an adapter 92.

The adapter 92 is cylindrical and has a threaded portion 99 for itsremovable mounting in either one of the tapped bores 94 in the casing.To facilitate the mounting of the adapter 92 in, or its removal from,the burner casing 22, the same is provided in this instance with ahexagonal head 101. An inner end length of the bores 62a and 62b iscounter-bored at 102 and 104, respectively, to the same diameter as thealigned bore 96 in the partition wall 36. The non-threaded length of theadapter 92 is of the same diameter as either one of the bores 96 in thepartition wall 36 of the burner casing, so that the mounted adapter ineither one of the bores 94 effectively seals thereat the chambers 38 and40 from each other and from the outside of the burner casing (Fig. 3).The adapter 92 is provided with a gas passage 110 which leads into atapped socket portion 112 for the reception of the threaded shank 70 ofa utility or dual-pressure gas burner tip 24. The outer end of the gaspassage 110 in the adapter 92 is tapped for the reception of a conduit114 which is in communication with any supply of flammable gas suitablefor pilot burner purposes. The body portion 72 and part of the head 64of the burner tip 24 is received in an enlarged end bore 116 in theadapter 92, and the remaining part of the head 64 of the installedburner tip is, in the example shown in Fig. 3, ttedly received in thebore 62a. When the pilot burner unit is installed as shown in Fig. 3,the body portion 72 of the burner tip 24 thereof is seated on an annularshoulder 118 in the adapter 92 so that only the longitudinalthrough-passage 76 in the burner tip 24 is in communication with the gaspassage in the adapter 92 for sustaining a pilot flame f at the flameend 77 of the tip (Fig. 3).

As previously mentioned, either one pilot burner unit 90 may be mountedin either one of the bores 94 in the burner casing 22, or a pilot burnerunit may be mounted in each of the bores 94 in the burner casing. Ineither case, the llame end of a pilot burner unit is in ignitingproximity to the flame ends of the next adjacent utility burner tips 24,so that the latter will be lighted as soon as the gas to the burnercasing 22 is turned on, and the arne from the thus ignited utilityburner tips 24 will soon propagate to the remaining utility burner tips.

In accordance with `a further aspect of the present invention,provisions are also made to permit the normal use of a dua1pressure gasburner tip 24 at one of the bores 62a or 62b in the burner casing ifonly one pilot burner unit 90 is used at the other one of these bores.Thus, assuming that only one pilot burner unit 90 is used in the presentburner, and that the same is installed at the bore 62a in the burnercasing (Figs. l and 3), recourse is had to a plug-type adapter 120 (Fig.5) to permit the normal use of a dual-pressure gas burner tip 24 at thebore 62b. The adapter 120 has a threaded plug end 122 and a sleeve-likeextension 124, of which the former is in this instance received in thattapped bore 94 in the burner casing which is in axial alignment withthe'bore 62b therein, while the cylindrical sleeve exten- 'sion 124 isttedly received in the aligned bore 96 in the partition wall 36 to sealthe high-pressure chamber 38 from the low-pressure chamber 40. Theadapter 120 is preferably provided with a hexagonal head 126 for itsready mounting in, or removal from, the easing 22. The sleeve extension124 of the adapter 120 has an internal passage 128 which leads to atapped socket portion 130 for the reception of the threaded shank 70 ofa dualpressure gas burner tip 24. The sleeve extension 124 of theadapter 120 is further provided in its peripheral wall with one or moreinlet duets 132 to provide communication between its passage 128 and thehigh-pressure chamber 38 of the casing. The sleeve extension 124 of theadapter 120 is of such longitudinal dimension that the burner tip 24installed therein assumes the same position in the bore 62b (Fig. 5) asdo all the other burner tips 24 in their respective bores 62 (Fig. 4).The burner tip 24 at the bore 62b, assembled with the adapter 120 asdescribed and mounted as shown in Fig. 5, performs like any of the otherburner tips 24, with the exception of the burner tip used in conjunctionwith the adapter 92 of the pilot burner unit 90. Thus, thethrough-passage 76 in the burner tip 24 at the bore 62b is incommunication with the high-pressure chamber 38 of the burner casing 22via the ducts 132 and passage 128 in the adapter 120, while thesecondary gas passages 82 along the head 64 of this burner tip are incommunication with the low-pressure chamber 40.

The bores 62 in the burner casing 22 are so spaced from each other, 'andthe flame ends 77 of the installed utility burner tips 24 are so exposedto the outside of the casing 22, that the flame ends 77 of these burnertips, including that of the burner tip of the pilot burner unit 90, arein igniting proximity to each other. cordingly, with the pilot burnerlighted, all the other burner tips 24 will be lighted on admitting gasinto the chambers 38 and 40 in the casing.

Reference is now had to Figs. 7 and 8, which show another feature of thepresent invention. Thus, the burner casing 22 may on its outside beprovided with widthwise restricted grooves or channels 140 whichlengthwise extend between successive bores 62, respectively, and servefor quick llame propagation from one burner tip to the others. Onadmission of gas into the casing 22 and according escape of gas from theburner tips 24, some gas will immediately accumulate in the channels140, and the gas thus accumulated therein will quickly ignite and theflame thereof propagate to all lburner tips if one of these burner tipsis lighted. This particular feature of the present invention isadvantageous regardless of whether the burner is or is not provided witha pilot burner unit. Thus, if the burner is provided with a pilot burnerunit or units, the llame or iiames thereof will immediately propagate toall remaining burner tips on admission of gas into the casing 22.However, if the present burner should not be provided with a pilotburner unit, the flame from any one of the utility burner tips 24,ignited in any manner whatsoever, will propagate to the remaining burnertips and ignite the same just as rapidly as if the burner were providedwith one or more pilot llames. Further, the instant flame-propagationchannels in the burner casing 22 are fully as advantageous if theutility burner tips should be single-pressure gas burner tips used formany purposes other than the ones for which the instant dual-pressuregas burner tips are especially applicable.

For more rapid accumulation of gas in the channels 140 in the burnercasing 22 and accordingly accelerated flame propagation to the variousburner tips, the channels 140 may be covered, except at their ends, asshown in Fig. 10. In the present instance, the flame-propagationchannels 146 are covered by a shield block 142 which is suitably mounted`at 144 on the outside of the burner casing 22, and provided with llameopenings 146 which are in axial `alignment with the mounted burner tips24, respectively (see also Fig. 9). The burner tips 24 are thuseffectively protected from dirt and other foreign matter, such aswiped-off solder in the manufacture of can bodies, for instance. Theshield block 142 may, if desired, be provided with a multiplicity ofcooling ribs 148.

Reference is now had to Fig. l1 which shows a modied arrangement of thename-propagation channels or grooves. In this instance, noflame-propagation channels are provided in the burner casing 22, andthey are instead provided at 140' in the shield block 142 betweensuccessive flame openings 146 therein, respectively.

The invention may be carried out in other speciic ways than those hereinset forth Without departing from the spirit and essentialcharacteristics of the invention, and the present embodiments are,therefore, to be considered in all respects as illustrative and notrestrictive, and all changes coming Within the meaning and equivalencyrange of the `appended claims are intended to be embraced therein.

I claim:

l. A dual-pressure gas burner, comprising a casing having separatechambers for high-pressure Iand lowpressure gas, respectively; a row ofupwardly inclined dual-pressure gas burner tips in said casing, each ofsaid burner tips having a flame end exposed to the outside of saidcasingin substantial igniting proximity to the ame ends of the next adjacentburner tips, and separate gas passages leading to said flame end andcommunicating with said chambers, respectively; and a shield blockmounted on the outside of said casing and having flame openings in linewith said burner tips, respectively, said shield block having adjacentsaid casing widthwise restricted grooves longitudinally extendingbetween adjacent flame openings, respectively, 'and serving for quickarne propagation to `all burner tips.

2. A dual-pressure gas burner, comprising a casing having an outer walland separate chambers for highpressure and low-pressure gas,respectively; a row of upwardly inclined dual-pressure gas burner tipsin said casing, each of said burner tips having a ame end exposed to theoutside of said casing in substantial igniting proximity to the flameends of the next adjacent burner tips, and separate gas passages leadingto said flame end and communicating with said chambers, respectively;and a shield block mounted on the outside of said casing and havingflame openings in line with said burner tips, respectively, said outercasing wall being provided with gro-oves of restricted widthslongitudinally extending between the iiame ends of adjacent burner tips,respectively, and serving for quick llame propagation to all burnertips, and said grooves being covered, except at their ends, by saidshield block for greater accumulation of gas therein and accordinglyaccelerated flame propagation to all burner tips.

3. A self-igniting dual-pressure gas burner, comprising a casing havingseparate chambers for high-pressure and low-pressure gas, respectively;a row of upwardly inclined dual-pressure gas burner tips in said casing,each of said burner tips having a flame end exposed to the outside ofsaid casing in substantial igniting proximity to the ame ends of thenext adjacent burner tips, and separate gas passages leading to said ameend and cornmunicating with said chambers, respectively; a pilot burnertip in said casing, said pilot burner tip having a flame end exposed tothe outside of said casing in substantial igniting proximity to theflame end of an adjacent dual-pressure gas burner tip, and a gas passageout of communication with said chambers; and a shield block mounted onthe outside of said casing and having flame openings in line with saidburner tips, respectively, said shield block having adjacent said casingwidthwise restricted grooves longitudinally extending between adjacentiiame openings, respectively, and serving for quick flame propagation toall dual-pressure gas burner tips.

4. A self-igniting dual-pressure gas burner, comprising a casing havingan outer wall and separate chambers for high-pressure'and low-pressuregas, respectively; a row of upwardly inclined dual-pressure gas burnertips in said casing, each of said burner tips having a flame end exposedto the outside of said casing in substantial igniting proximity to theflame ends of the next adjacent burner tips, and separate gas passagesleading to said iiame end and communicating with said chambers,respectively; a pilot burner tip in said casing, said pilot burner tiphaving a ame end exposed to the outside of said casing in substantialigniting proximity to the iiame end of an adjacent dual-pressure gasburner tip, and a gas passage out of communication with said chambers;and a shield block mounted on the outside of said casing and having ameopenings in line with said burner tips, respectively, said outer casingwall being provided with grooves of restricted widths longitudinallyextending between the ame ends of adjacent burner tips, respectively,and serving for quick flame propagation to all dual-pressure gas burnertips, and said grooves being covered, except at their ends, by saidshield block for greater accumulation of gas therein and accordinglyaccelerated flame propagation to all dual-pressure gas burner tips.

5. A self-igniting dual-pressure gas burner, comprising a casing havingan outer wall and an internal partition wall dividing said casing intofirst and second chambers for high-pressure and low-pressure gas,respectively, said casing also having substantially parallel first andsecond sets of axially aligned holes of which those of said first setextend through the outer wall of said second chamber and through saidpartition wall, respectively, and the holes of said second set are oflarger cross-sectional dimensions than those of said first set andextend through said partition wall and through the outer walls of saidchambers, respectively; a first utility burner tip received with itsouter flame end and with its inner end in the holes of said first set inthe outer wall of said second chamber and in said partition wall,respectively, and having separate first and second gas passages leadingto said flame end and communicating with said first and second chambers,respectively; another utility burner tip identical with said firstburner tip; and a sleeve-type adapter extending through said chambersand holes of said second set and removably mounted in the latter inclosing relation therewith, and having a gas passage out ofcommunication with said chambers, said adapter internally removablyreceiving said other burner tip with said first and second gas passagesthereof in and out of communication, respectively, with said adapter gaspassage and with its tiame end exposed to the outside of said casing inigniting proximity to the flame end of said first burner tip, whereforesaid other utility burner tip serves as a single gas pressure type pilotburner tip.

6. A dual-pressure gas burner as set forth in claim 5, in which an outerlength of the hole of said second set through the outer wall of saidsecond chamber is reduced to the same cross-sectional shape anddimension as the hole of said first set through the same outer wall ofsaid second chamber and fittedly receives the tiame end of said otherburner tip, and said adapter is fittedly received in thecross-sectionally non-reduced remainder ot the hole having said reducedlength.

7. A dual-pressure gas burner, comprising a casing having an outer Walland an internal partition Wall dividing said casing into first andsecond chambers for highpressure and low-pressure gas, respectively,said casing having axially aligned holes in said partition wall and theouter walls of said chambers, respectively; a plug-type adapterextending through said first chamber and mounted in said hole in theouter wall of said first chamber in closing relation therewith, saidadapter being provided with a sleeve extension iittedly received in saidhole in said partition wall and having an aperture providingcommunication between said iirst chamber and the interior of said sleeveextension; and a burner tip received with its inner end in said sleeveextension, said burner tip having an opposite flame end fittedlyreceived in said hole in the outer wall of said second chamber, andseparate gas passages leading to said liame end and communicating withthe interior of said sleeve extension and said second chamber,respectively.

S. A dual-pressure gas burner as set forth in claim 7, in which saidplug-type adapter is threadedly received in said hole in the eater wallof said first chamber, and the inner end of said burner tip isthreadedly received in said sleeve extension, so that said adapter andburner tip may bc removed from said casing and from each other.

9. A gas burner, comprising a gas-distributing casing having an outerwall; holes through said outer wall and burner tips disposed thereineach having a flame end exposed at said outer wall to the outside of thecasing, said outer casing wall being provided with a groove ofrestricted cross-sectional arca longitudinally extending between theflame ends of said tips; and a cover over said groove to define with thelatter a conduit open at its opposite ends, said conduit endsterminating substantially at the points of their intersection withadjacent burner tip holes in said casing.

lti

10. A self-igniting dual-pressure gas burner, comprising acasing havingwall means defining separate first and second chambers for high-pressureand low-pressure gas, respectively, said wall means including apartition wall between the chambers and having formed therein a firstset of axially aligned holes, one of the holes of said set extendingthrough said partition wall and another through an exterior wall of saidcasing, whereby said holes provide communication between said chambersand between one of them and the outside of said casing; said wall meansalso having formed therein a second set of axially aligned holesadjacent said first set and parallel thereto, the holes of said secondset extending through said partition wall and through oppositelydisposed exterior walls of said chambers to provide communicationbetween said chambers and between each of them and the exterior of theeasing; a first utility burner tip mounted in said first set of holes,said burner tip having a tiame end disposed in the hole opening on theexterior of said casing and separate first and second gas passagesleading to said flame end and communicating with said first and secondchambers, respectively; another utility burner tip identical with saidfirst tip and mounted in said second set of holes; and a sleeve-typeadapter extending in said second set of holes through said chambers,said adapter being snugly received by the peripheries of said holes ingastight engagement therewith, said adapter internally receiving saidother burner tip with the flame end thereof exposed to the outside ofsaid casing in igniting proximity to the flame end of said first burnertip, said adapter having a gas passage out of communication with saidchambers and in and out of communication with said first and second gaspassages, respectively, of said other burner tip, wherefore said otherutility burner tip serves as a single gas pressure type pilot burnertip.

1l. A self-igniting dual-pressure gas burner as set forth in claim l0,in which said adapter is removably mounted in said second set of holes,and said other burner tip is removably received by said adapter, so thatsaid other burner tip and adapter may be removed from each other andfrom said casing.

l2. A self-igniting dual-pressure gas burner comprising a casing havingwall means defining separate highpressure and low-pressure gas chambers,said wall means including a partition wall between the chambers andhaving formed therein a plurality of sets of holes, the holes of eachset being axially aligned, one hole of each set extending through saidpartition wall and another through an exterior wall of said low-pressurechamber, said sets lof holes being spaced along the burner and providingcommunication between the chambers and between the low-pressure chamberand the exterior ot said casing; at least two of said sets of holescomprising pilot burner sets and said wall means having at each of theselocations a hole through an exterior wall of said high-pressure chamberin axial alignment with the other holes in the respective sets, wherebysaid two sets of pilot burner holes provide communication between saidchambers and between 'each of them and the exterior of said casing, saidpilot burner holes being separated by a plurality of the other sets ofholes in said casing; a burner tip mounted in each set of holes, eachtip being identical in construction with the others and each having aflame end exposed to the voutside of said casing in igniting proximityto the flame ends of the next adjacent burner tips, and separate firstand second gas passages leading to said flame end and, 'except for thetips in said pilot burner holes, communicating with said high and lowpressure chambers, respectively; a sleeve-type adapter extending throughboth said chambers and mounted in the holes of one of said sets of pilotburner holes in closing relation therewith, said said tip communicateswith said adapter gas passage, whereby said one burner tip serves as aself-contained single-pressure gas pilot burner tip; and anotherplug-like adapter removably mounted in, and in gas-tight engagementwith, the holes in said high-pressure chamber and partition wall of theother set of pilot burner holes, said plug-li e adapter having a socketfor the removable reception of the burner tip therein, whereby thesecond gas passage of said last said burner tipv communicates with saidlow-pressure chamber while said rst gas passage thereof communicateswith said socket, and said plug-like adapter has an aperture formedthrough its wall to provide communication between its socket and saidhighpressure chamber.

13. A gas burner, comprising an enclosed gas-distributing casing havingan outer wall part; holes through said outer wall part; burner tipsdisposed in each having a llame end exposed at said outer wall part tothe outside of said casing; a cover part on said wall part having flameapertures spaced to coincide with said holes in said outer wall part;one of said parts being provided with a laterally open narrow groove ofrestricted cross-sectional area extending longitudinally of said casingbetween adjacent burner tips; said parts defining between them coveredflame propagating conduit means open only at the intersection of saidconduit means with said burner tip holes.

References Cited in the le of this patent UNITED STATES PATENTS 791,923Machlet June 6, 1905 1,151,327 Andreas Aug. 24, 1915 1,204,359 Kemp etal Nov. 7, 1916 2,038,749 Martn Apr. 28, 1936 2,059,360 Keith Nov. 3,1936 2,533,143 Scharbau et al. Dec. 5, 1950 2,547,276 Marsh et al Apr.3, 1951 2,596,229 Flynn May 13, 1952 2,599,457 Jones June 3, 19522,633,190 Kerwin et al. Mar. 31, 1953 2,648,377 Bodey Aug. 11, 1953FOREIGN PATENTS 51,010 Denmark Dec. 9, 1935

